Merge branch 'ax25-fix-issues-of-ax25_dev-and-net_device'

Duoming Zhou says:

====================
ax25: Fix issues of ax25_dev and net_device

The first patch uses kernel universal linked list to implement
ax25_dev_list, which makes the operation of the list easier.
The second and third patch fix reference count leak issues of
the object "ax25_dev" and "net_device".
====================

Link: https://lore.kernel.org/r/cover.1715247018.git.duoming@zju.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Jakub Kicinski 2024-05-13 16:09:40 -07:00
commit f440092bc5
2 changed files with 17 additions and 34 deletions

View File

@ -216,7 +216,7 @@ typedef struct {
struct ctl_table;
typedef struct ax25_dev {
struct ax25_dev *next;
struct list_head list;
struct net_device *dev;
netdevice_tracker dev_tracker;
@ -330,7 +330,6 @@ int ax25_addr_size(const ax25_digi *);
void ax25_digi_invert(const ax25_digi *, ax25_digi *);
/* ax25_dev.c */
extern ax25_dev *ax25_dev_list;
extern spinlock_t ax25_dev_lock;
#if IS_ENABLED(CONFIG_AX25)

View File

@ -22,11 +22,12 @@
#include <net/sock.h>
#include <linux/uaccess.h>
#include <linux/fcntl.h>
#include <linux/list.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/init.h>
ax25_dev *ax25_dev_list;
static LIST_HEAD(ax25_dev_list);
DEFINE_SPINLOCK(ax25_dev_lock);
ax25_dev *ax25_addr_ax25dev(ax25_address *addr)
@ -34,10 +35,11 @@ ax25_dev *ax25_addr_ax25dev(ax25_address *addr)
ax25_dev *ax25_dev, *res = NULL;
spin_lock_bh(&ax25_dev_lock);
for (ax25_dev = ax25_dev_list; ax25_dev != NULL; ax25_dev = ax25_dev->next)
list_for_each_entry(ax25_dev, &ax25_dev_list, list)
if (ax25cmp(addr, (const ax25_address *)ax25_dev->dev->dev_addr) == 0) {
res = ax25_dev;
ax25_dev_hold(ax25_dev);
break;
}
spin_unlock_bh(&ax25_dev_lock);
@ -59,7 +61,6 @@ void ax25_dev_device_up(struct net_device *dev)
}
refcount_set(&ax25_dev->refcount, 1);
dev->ax25_ptr = ax25_dev;
ax25_dev->dev = dev;
netdev_hold(dev, &ax25_dev->dev_tracker, GFP_KERNEL);
ax25_dev->forward = NULL;
@ -85,10 +86,9 @@ void ax25_dev_device_up(struct net_device *dev)
#endif
spin_lock_bh(&ax25_dev_lock);
ax25_dev->next = ax25_dev_list;
ax25_dev_list = ax25_dev;
list_add(&ax25_dev->list, &ax25_dev_list);
dev->ax25_ptr = ax25_dev;
spin_unlock_bh(&ax25_dev_lock);
ax25_dev_hold(ax25_dev);
ax25_register_dev_sysctl(ax25_dev);
}
@ -111,32 +111,19 @@ void ax25_dev_device_down(struct net_device *dev)
/*
* Remove any packet forwarding that points to this device.
*/
for (s = ax25_dev_list; s != NULL; s = s->next)
list_for_each_entry(s, &ax25_dev_list, list)
if (s->forward == dev)
s->forward = NULL;
if ((s = ax25_dev_list) == ax25_dev) {
ax25_dev_list = s->next;
goto unlock_put;
}
while (s != NULL && s->next != NULL) {
if (s->next == ax25_dev) {
s->next = ax25_dev->next;
goto unlock_put;
list_for_each_entry(s, &ax25_dev_list, list) {
if (s == ax25_dev) {
list_del(&s->list);
break;
}
s = s->next;
}
spin_unlock_bh(&ax25_dev_lock);
dev->ax25_ptr = NULL;
ax25_dev_put(ax25_dev);
return;
unlock_put:
spin_unlock_bh(&ax25_dev_lock);
ax25_dev_put(ax25_dev);
dev->ax25_ptr = NULL;
spin_unlock_bh(&ax25_dev_lock);
netdev_put(dev, &ax25_dev->dev_tracker);
ax25_dev_put(ax25_dev);
}
@ -200,16 +187,13 @@ struct net_device *ax25_fwd_dev(struct net_device *dev)
*/
void __exit ax25_dev_free(void)
{
ax25_dev *s, *ax25_dev;
ax25_dev *s, *n;
spin_lock_bh(&ax25_dev_lock);
ax25_dev = ax25_dev_list;
while (ax25_dev != NULL) {
s = ax25_dev;
netdev_put(ax25_dev->dev, &ax25_dev->dev_tracker);
ax25_dev = ax25_dev->next;
list_for_each_entry_safe(s, n, &ax25_dev_list, list) {
netdev_put(s->dev, &s->dev_tracker);
list_del(&s->list);
kfree(s);
}
ax25_dev_list = NULL;
spin_unlock_bh(&ax25_dev_lock);
}